Recent EP Published Guidance Guidance published by IRS related to retirement plans. Archive of Published Guidance Retirement plan guidance by type - October 2000 to date Interest Rates Tables Find out the monthly weighted-average interest rates that apply to your retirement plan. Actuarial Tables Use these actuarial tables to value annuities, life estates, remainders and reversions. For examples on how to use the tables, refer to IRS publications listed. Actuarial Private Letter Rulings This list of tips and common errors will help reduce processing delays and improve your experience with the actuarial private letter ruling process. Priority Guidance Plan Information relating to the Priority Guidance Plan, including links to both the current and prior versions, and news or notices about the Plan. Advance Releases Text of revenue rulings, revenue procedures, and other technical items in advance of their Internal Revenue Bulletin publication date Tax code, regulations, and official guidance Different sources provide the authority for tax rules and procedures. Here are some sources that can be searched online for free. Pension Plan Mortality Tables Find the mortality tables and mortality improvement rates that apply to your pension plan.